Walking with a haptic tensile force applied to the hand in a virtual environment (VE) can induce adaptation effects in both chronic stroke and non-stroke individuals. These effects are reflected in spatiotemporal outcomes such as gait speed. However, the concurrent kinematic changes occurring in bilateral lower limb coordination have yet to be explored. Chronic stroke participants were stratified based on overground gait speed into lower functioning (LF < 0.8 m/s, N = 7) and higher functioning (HF ≥ 0.8 m/s, N = 7) subgroups. These subgroups and an age-matched control group (N = 14, CG) walked on a self-paced treadmill in a VE with either robot-generated haptic leash forces delivered to the hand and then released or with an instrumented cane. Walking in both leash (10 and 15 N) and cane conditions were compared to pre-force baseline values to evaluate changes in lower limb coordination outcomes. All groups showed some kinematic changes in thigh, leg and foot segments when gait speed increased during force and post-force leash as well as cane walking. These changes were also reflected in intersegmental coordination and 3D phase diagrams, which illustrated increased intersegmental trajectory areas (p < 0.05) and angular velocity. These increases could also be observed when the paretic leg transitions from stance to swing phases while walking with the haptic leash. The Sobolev norm values accounted for both angular position and angular velocity, providing a single value for potentially quantifying bilateral (i.e. non-paretic vs paretic) coordination during walking. These values tended to increase (p < 0.05) proportionally for both limbs during force and post-force epochs as gait speed tended to increase. Individuals with chronic stroke who increased their gait speed when walking with tensile haptic forces and immediately after force removal, also displayed moderate concurrent changes in lower limb intersegmental coordination patterns in terms of angular displacement and velocity. Similar results were also seen with cane walking. Although symmetry was less affected, these findings appear favourable to the functional recovery of gait. Both the use of 3D phase diagrams and assigning Sobolev norm values are potentially effective for detecting and quantifying these coordination changes.

中文翻译：

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在虚拟环境中使用机器人产生的触觉力行走：一种分析下肢协调的新方法

在虚拟环境 (VE) 中将触觉张力施加到手上行走可以在慢性中风和非中风个体中引起适应效应。这些影响反映在时空结果上，例如步态速度。然而，双侧下肢协调中同时发生的运动学变化还有待探索。慢性卒中参与者根据地面步态速度分为低功能（LF < 0.8 m/s，N = 7）和功能较高（HF ≥ 0.8 m/s，N = 7）亚组。这些亚组和一个年龄匹配的对照组（N = 14，CG）在 VE 中的自定进度跑步机上行走，机器人产生的触觉牵引力传递到手上然后释放，或者使用仪器化的手杖。将牵引带（10 和 15 N）和手杖条件下行走与预受力基线值进行比较，以评估下肢协调结果的变化。当在用力和后用力牵引以及手杖行走期间步态速度增加时，所有组都显示出大腿、腿部和足部的一些运动学变化。这些变化也反映在节间协调和 3D 相图中，这表明节间轨迹区域 (p < 0.05) 和角速度增加。当使用触觉皮带行走时，麻痹腿从站立阶段过渡到摆动阶段时，也可以观察到这些增加。Sobolev 范数值同时考虑了角位置和角速度，为可能量化步行期间的双边（即非麻痹与麻痹）协调提供了一个单一的值。随着步态速度趋于增加，这些值在受力期间和受力后时期对于双肢成比例地增加 (p < 0.05)。患有慢性中风的个体在用张力触觉力行走时和移除力后立即增加步态速度，在角位移和速度方面也显示出下肢节间协调模式的适度并发变化。手杖行走也有类似的结果。虽然对称性受到的影响较小，但这些发现似乎有利于步态的功能恢复。3D 相图的使用和分配 Sobolev 范数值对于检测和量化这些协调变化都可能有效。患有慢性中风的个体在用张力触觉力行走时和移除力后立即增加步态速度，在角位移和速度方面也显示出下肢节间协调模式的适度并发变化。手杖行走也有类似的结果。虽然对称性受到的影响较小，但这些发现似乎有利于步态的功能恢复。3D 相图的使用和分配 Sobolev 范数值对于检测和量化这些协调变化都可能有效。患有慢性中风的个体在用张力触觉力行走时和移除力后立即增加步态速度，在角位移和速度方面也显示出下肢节间协调模式的适度并发变化。手杖行走也有类似的结果。虽然对称性受到的影响较小，但这些发现似乎有利于步态的功能恢复。3D 相图的使用和分配 Sobolev 范数值对于检测和量化这些协调变化都可能有效。还显示下肢节间协调模式在角位移和速度方面的适度并发变化。手杖行走也有类似的结果。虽然对称性受到的影响较小，但这些发现似乎有利于步态的功能恢复。3D 相图的使用和分配 Sobolev 范数值对于检测和量化这些协调变化都可能有效。还显示下肢节间协调模式在角位移和速度方面的适度并发变化。手杖行走也有类似的结果。虽然对称性受到的影响较小，但这些发现似乎有利于步态的功能恢复。3D 相图的使用和分配 Sobolev 范数值对于检测和量化这些协调变化都可能有效。